They are spread by air, water, in food, and by bodily fluids
100
What is the envelope?
A membrane-like covering for capsids of some viruses
100
Why are viruses not considered living?
The lack some of the key characteristics of living organisms
100
What are the genes that can cause cancer?
Oncogene
100
Define a virus?
A virus is a non-living particle made up of nucleic acid and a protein coat or a nucleic acid and a lipid-protein coat
200
What does a virus need in order to replicate?
A host cell's enzymes and organelles
200
What is a capsid?
A protein coat that is the only layer surrounding some viruses
200
What forms the envelope?
The nuclear membrane or the cell membrane of the host cell
200
What disease can occur later in a person's life as a result of previously contracting chicken pox?
Shingles
200
What do virulent viruses do?
Destroy the cell they infect.
300
What makes up a bacteriophage?
They have capsids and a protein tail
300
What is a temperate virus?
Any virus that replicates through the lysogenic cycle
300
What is the shape of a virus caused by?
Its genome and protein coat
300
What is a combination of two or more drugs referred to as?
Cocktail
300
What are three ways to fight viruses?
Vaccinations, Vector Control, and Drug therapy
400
What are the first three steps a virus goes through during the lysogenic cycle?
First the viral DNA integrates into the host DNA. Second the viral DNA is replicated. Lastly, the prophage may leave the host DNA and enter the lytic cycle
400
What is a prion?
Infectious protein particles that do not have a genome
400
What help new viruses recognize host cells?
Protein in the envelope
400
What disease, caused by sexual contact, gradually destroys a person's immune system?
HIV
400
What was the first virus to be crystalized?
TMV
500
What are the five steps that a virus goes through during the lytic cycle?
First the virus attaches to a cell and injects DNA. Second the viral DNA circularizes. Third the viral DNA continues the lytic cycle. Fourth new viruses are made. Lastly the viruses are released from the cell by causing the host cell to rupture
500
What is reverse transcriptase?
An enzyme that catalyzes the formation of DNA from an RNA template
500
How are viruses classified?
By whether they have RNA or DNA based on the nature of their capsid and on the presence or absence of an envelope
500
Identify four viral diseases that result in serious human illness?
Flu, chicken pox, measles, polio, and viral hepatitis
500
Glycoproteins on the surface of HIV bind to what, specifically?